The invention relates to a cutter plate for precision working, especially of holes, which is constructed as a symmetrical polygon with at least four corners and has at least one main cutting edge and one auxiliary cutting edge, as well as a projection which begins at chip run-off surfaces of the cutting edges, whose sides serve as chip-guiding steps. In addition, the invention relates to a process for the manufacture of such a cutter plate.
The precision working of workpieces, especially of the walls of holes, by chip-removal processes, is becoming more and more important, because in this way a subsequent working by honing and/or by other supplemental processes can be eliminated. It is especially important in the precision or fine working of workpieces to have the correct flow of chips and the chip breakage which occurs as a result. Only in this way can it be assured, in the precision working of holes, that there is no formation of chips of excessive length, which would lead to an accumulation of chips, which in turn would impair the quality of the surface being processed. An important drawback of known cutter plates is also that their manufacture is very costly.
A cutter plate of the kind mentioned at the outset is already known from FIG. 15 of German Preliminary Pat. No. DE-OS 26 15 589. There a total of four cutting corners or angles is provided, where a chip surface is associated with each cutting corner and is made up of two mutually intersecting surface elements, which come together in the curvature-bisecting plane of the cutting corner at an arc of curvature. This is seen particularly in FIG. 26. The production of a cutter plate shaped in this way is extremely complicated, as well as time-consuming, and is therefore costly. In particular, only special working tools can be used, which must be changed repeatedly during the manufacturing operation. Furthermore, it is necessary to use repeated rechucking operations on the cutter plate being manufactured. It is also possible to manufacture the cutter plate by a sintering procedure, but the edge radii which are produced in this way are unsuitable for precision or fine working.